Method of assembling a light emitting device with an optical fiber

ABSTRACT

A light emitting device including a light emergence device, an optical fiber for receiving light emerging from the light emergence device, and an optical fiber supporting member having a groove or hole for accommodating and fixing the optical fiber. The support member is adapted to be deformed when subjected to an external force so as to enable an alignment of the optical axes of the light emergence device and the optical fiber.

This is a continuation of Ser. No. 085,761, filed Aug. 17, 1987 (nowU.S. Pat. 4,834,492).

BACKGROUND OF THE INVENTION

The present invention relates to light emitting devices and, moreparticularly, to a light emitting device effective as a light emittingsource for optical communications.

In, for example, applicants' U.S. Ser. No. 524,324 a laser diode devicewith an optical fiber is proposed which employs a laser diode chip.However, it has been determined that in this proposed device, in someinstances, there is a deviation in the optical axis of the optical fiberand the chip thereby resulting in a non-conforming product.

The aim underlying the present invention essentially resides inproviding a light emitting device having a high photocoupling efficiencybetween a light emitting element and an optical fiber for transmittingradiation, emitted from the light emitting element, out of the lightemitting device.

An object of the present invention resides in providing a light emittingdevice which has a high available precentage of production and whichminimizes the occurrence of defective light emitting devices.

In accordance with advantageous features of the present invention, anoptical communication device is provided wherein a light emitting chipelement and a photocoupled end part of an optical fiber are fixedlydisposed in opposition to each other along a principal or main surfaceof a stem, with the photocoupled end part of the optical fiber extendingthrough a resin provided in a hole or opening formed in a flexiblesupport member fixed to the stem. The photocoupled state between thechip element and the optical fiber is tested while the radiation isemitted from the chip element, and when the test reveals an inferiorphotocoupled state, an external force is exerted in a desired directionon the head part of the support member so as to readjust the position ofthe photocoupled end of the optical fiber, whereby the photocouplingefficiency can be significantly enhanced. Consequently, it is possibleto provide a high percentage production of the optical communicationdevices with each of the devices having a favorable photocouplingefficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a laser diode device with an opticalfiber constructed in accordance with U.S. Ser. No. 524,324;

FIG. 2 is a plan view of a laser diode device with an optical fiberconstructed in accordance with the present invention;

FIG. 3 is a cross-sectional view taken along the line III--III' in FIG.2;

FIG. 4 is an enlarged cross-sectional view of a portion of the device ofFIG. 2;

FIG. 5 is a perspective view of an arrangement for adjusting a positionof a support member of the device of FIG. 2;

FIG. 6 is a perspective view of another embodiment of a support memberfor a laser diode device constructed in accordance with the presentinvention;

FIG. 7 is a perspective view of yet another embodiment of a supportmember for a laser diode device constructed in accordance with thepresent invention;

FIG. 8 is a cross-sectional view of a laser diode device with an opticalfiber constructed in accordance with another embodiment of the presentinvention;

FIG. 9 is a perspective view of an optical fiber support member for afurther embodiment of a laser diode device constructed in accordancewith the present invention.

FIG. 10 is a perspective view of another embodiment of an optical fibersupport member for a laser diode device constructed in accordance withthe present invention; and

FIG. 11 is a perspective view of an optical fiber support member ofstill another embodiment of the present invention.

DETAILED DESCRIPTION

Referring now to the drawings wherein like reference numerals are usedthroughout the various views to designate like parts and, moreparticularly, to FIG. 1, according to this figure, a laser diode deviceof the type proposed U.S. Ser. No. 524,324 includes a laser diode chip 3fixed to a principal or main surface of a stem 1 by a submounting member2 by, for example, solder 4, 5. An optical fiber 7 is supported by afiber guide 6, fixed to and extending through a peripheral wall of thestem 1, with a photocoupled end 8 of the optical fiber 7 confronting anexit face of the chip 3. Laser radiation 9,emerging from the exit faceof the chip is received in the optical fiber 7 from the photocoupled endthereof, and is transmitted out of the laser diode device, with theoptical fiber 7 being employed as a transmission medium of the laserradiation 9. Additionally, the photocoupled end of the optical fiber 7is inserted in a hole or opening 11 formed in a projecting supportmember 10 provided in the principle surface of the stem 1, with thephotocoupled end 8 being fixed by a fixing material such as, forexample, a resin or solder 12 which fills the hole or opening 11. Thehole or opening 11 is designed or constructed such that a center thereofcorresponds to a central part of the exit face of the chip 3, and theoptical fiber 7, inserted in the hole or opening 11, has a holecircumference thereof drawn out by a uniform force when the fixingmaterial is cured, whereby the optical fiber can be located at thecenter of the hole or opening 11 even after a curing of the fixingmaterial 12. Therefore, the light receiving efficiency or photocouplingefficiency of the fiber 7 is relatively high. The fiber guide 7 ishermetically fastened to the stem 1 with, for example, a silver paste13, and the optical fiber 7 is fixed to the fiber guide 6 with, forexample, a resin 14.

As noted above, with a laser diode device such as constructed in themanner illustrated in FIG. 1, the optical axes of the optical fiber 7and the chip 3 sometimes deviate and efforts to reveal the causes forthe deviation or misalignment of the optical axis resulted indiscovering the following factors.

The alignment of the optical axes of the laser radiation 9 and theoptical fiber 7 is carried out in such a manner that the photocoupledend of the optical fiber 7, inserted in the fiber guide 6, is insertedinto the hole or opening 11 of the support member 10, whereupon theliquid resin fixing material 12 is packed in the hole or opening 11,with the optical fiber 7 being uniformly drawn or pulled in a peripheraldirection thereof by the adhesive force of the resin 12 so as to becentrally located in the circular hole or opening 11. In aligning theoptical axes, the fine front end part of the fiber guide 6 has aposition thereof adjusted by applying an external force thereto, to seekthe position at which the laser radiation 9, emerging from the fixedchip and received into the optical fiber 7, can be maximized. When theposition of the optical fiber 7 at which the maximum laser radiation 9can be received is determined in this manner, the liquid resin fixingmaterial 12 is poured into the hole or opening 11 and is thermally curedto fix the front end 8 of the optical fiber 7. Accordingly, immediatelyafter the liquid resin fixing material 12 is packed into the hole oropening 11 and has been thermally cured, the optical axes of the laserradiation 9 and the optical fibers 7 should be at a state wherein thephotocoupling efficiency is maximized. However, as noted above, in someinstances, after the liquid resin fixing material 12 has been thermallycured, the position of the optical fiber sometimes deviates to the pointof extensively lowering the light receiving efficiency thereof.

One reason for this deviation resides in the fact that when, beforepouring the liquid resin fixing material 12, the front end of the fiberguide 6 is deformed to align the optical axes of the optical fiber 7 andlaser chip 3, a residual stress is created in the fiber guide 6, and,when heat is applied for thermally curing the fixing material 12, insome instances, the fiber guide 6, having the residual stress, isdeformed so that the position of the front end part 8 of the opticalfiber 7 deviates or fluctuates resulting in a misalignment of theoptical axes.

The positional deviations of the optical fiber may also occur due toheat treatments at, for example, 70° C. which heat treatments occur forat least twenty minutes, and which heat treatments are involved in theconnection between a lead and a gold wire, the sealing fixation or seamwelding of a cap for hermetic sealing, etc. However, it has beendetermined that these positional deviations of the optical fiber 7 areinfrequent, and that the misalignment of the optical axes in principallyincurred during the thermal curing of the resin 12. It has been foundthat the deviation magnitude of the position of the optical fiber 7arising on this occasion is approximately 0.2-0.4 μm and exceeds 0.1-0.2μm, the allowable deviation value of the optical axes, so that aninferior alignment of the optical axes occurs.

As shown most clearly in FIGS. 2 and 3, in accordance with the presentinvention, a stem 1, formed as an oblong metal plate, has one surfacethereof machined so as to form a ring-shaped sealing wall 15 in acentral part thereof, with an inner side of the ring-shaped sealing wall15 being hollowed out to a still greater extent so as to form a pedestalportion 16 centrally of a bottom of the hollow.

As shown in FIG. 4, the submount member 2 is fixed on the pedestalportion 16 by, for example, solder 5, with the laser diode chip 3 beingfixed to the submount member 2 with, for example, solder 4. Guide holesgenerally designated by the reference numerals 17, 18 are respectivelyprovided at both the ends of the stem 1, with the guide holes 17, 18extending toward the exit faces of the chip 3 from which the laserradiation 9 emerges. A fiber guide 6, having a single-mode optical fiber7 centrally and snugly inserted and fixed therein, is fitted into oneguide hole 17 and is fixed to the stem 1 with, for example, a silverpaste 13. The front end of the optical fiber 7 confronts one exit faceof the chip 3 so as to receive the laser radiation 9 into the opticalfiber 7. A photocoupled end 8, at the front end of the optical fiber 7,is inserted into a circular hole 21 provided in a support membergenerally designated by the reference numeral 20 formed as a round rodof, for example, Kovar, with the support member 20 being fixed to thepedestal portion 16 of the stem 1 by, for example, a silver paste 19,and with the photocoupled end 8 being fixed in the hole 21 by a fixingmaterial 22 packed therein.

A monitor fiber 23 is snugly inserted and fixed in the guide hole 18,with a front end portion 8a of the monitor fiber 23 confronting theother exit face of the chip 3 so as to monitor the light intensity ofthe laser radiation 9. Two leads 24, 25 are disposed in the stem 1, withone lead 24 being a ground lead welded to the stem 1 and electricallyconnected to a lower electrode of the chip 3 through the stem 1 and thesubmount member 2, and the lead 25 being fixed to the stem 1 through aninsulator (not shown) such as, for example, glass. An inner end of thelead 25 extends through the end face of the stem 1 to a space locatedinteriorly of the ring-shaped sealing wall 15, with the inner ends ofthe lead 25 and upper electrode of the chip 3 being electricallyconnected by a lead or wire 26 made of, for example, gold. A flat cap 27is hermetically mounted on a top of the ring-shaped sealing wall 15 byseam welding so as to hermetically encapsulate the chip 3, etc.Additionally, mounting holes 28, used during a packaging operation, areprovided at least at four corners of the stem 1.

The laser diode device of the present invention may be manufactured inthe following manner.

After the stem 1 has been prepared, the fiber guide 6, support member20, and monitor fiber 23 are fixed with the silver paste 13. Thereafter,the submount member 2, to which the chip 3 is fixed, is positioned andfixed on the pedestal portion 16 of the stem 1 with the solder 5. Theupper electrode (not shown) of the chip 3, disposed on the upper surfaceof the chip 3, and the lead 25 are connected by the wire 26.

Subsequently, the optical fiber 7 is inserted into the fiber guide 6,and the photocoupled end 8 is inserted into the hole 21 of the supportmember 20 so as to confront the exit face of the chip 3. As shown inFIG. 4, in the front end part of the optical fiber 7, the clad layer ofthe optical fiber 7 is polished with a taper such as, for example,pencil tip, and the core thereof has its extreme end spherically workedso as to have a curvature. The spherically worked part of the corefunctions as a lens so that the laser radiation 9 can be efficientlyreceived into the optical fiber 7. Next, using a fixing material 29 madeof, for example, a resin, the optical fiber 7 is fixed at the front endpart of the fiber guide 6, and the hole of the fiber guide 6 is closed.

In this state, with a predetermined voltage applied to the chip 3 so asemit light, an optical output is received in the optical fiber with thereceived optical output in the optical fiber 7 being detected. In orderto maximize the optical output, the front end part of the fiber guide 6is finely adjusted in all directions, whereby the photocoupled end 8 isadjusted so as to lie centrally of the hole 21. When the photocoupledend part 8 of the optical fiber 7 is positioned centrally of the hole21, the photocoupling efficiency is maximized.

The liquid resin fixing material 22 is packed into the hole 21 of thesupport member 20, which fixing material 22 has an adhesive force. Theoptical fiber 7 may, for example, have an outside diameter of, forexample, 125 μm, with a diameter of the hole 21 being, for example, 400μm and they are proximate. Therefore, a pulling force acts between aperipheral surface of the optical fiber 7 and that of the hole 21 due tothe adhesive force of the fixing material 22. Additionally, since thehole 21 is circular in cross section, the fixing material 22, existingin the whole peripheral part of the optical fiber 7, is uniformlydistributed so that the whole peripheral surface is radially pulled ordrawn by a uniform force, and the optical fiber 7 is automaticallycentrally positioned in the hole 21.

A heat treatment is then performed so as to cure the fixing material 22in the hole 21. The temperature of the heat treatment is set at a lowtemperature of, for example, 70° C. in order to prevent a degradation ofa jacket 30 which covers the optical fiber 7.

Next, a detection of the optical fiber is once again executed or carriedout and, if the optical output has decreased, as shown in FIG. 5, thesupport member 20 is slightly curved with a correcting tool 31. As canreadily be appreciated, other means than the correcting tool 31 may beused for carrying out the corrective alignment. The correcting tool 31is provided, at a lower end surface thereof, with an inserting hole 32for accommodating the support member 20 so as to receive a head portionof the support member 20 in the inserting hole 32, whereupon the supportmember 20 is slightly bent or inclined to adjust the photocoupled end 8so that the optical output in the optical fiber 7 is maximized. When thehead part of the support member 20 is inclined or bent downwardly towardthe chip 3, the photocoupled end 8 swings in a downward direction and,when the head part of the support member 20 is displaced in the oppositedirection, the photocoupled end 8 moves in an upward direction.Additionally, when the head part of the support member 20 is moved in alateral direction, the photocoupled end 8 moves laterally along theprinciple surface of the stem 1. The height W₁ of the hole 21 of thesupport member 20 and the length W₂ from the hole 21 to the head part ofthe support member 20 is advantageously set at relatively great valuesso as to prevent the correcting tool 31 from touching and breaking theoptical fiber 7 when the support member 20 is bent or inclineddownwardly. For this reason, the relationship between W₁ and W₂ shoulddesireably be W₂ >W₁. Additionally, when the head part of the supportmember 20 is subjected to a force, the support member 20 curves or bendsfrom the root part thereof, and the extent of curve or the extent offall increases toward the head part. Consequently, as W₂ is madegreater, a slighter force for moving the tool 31 is sufficient foradjusting the position of the front end of the optical fiber 7, so as tofacilitate adjustments. In order to permit the support member 20 to beeasily plastically deformed with a relatively small force, the supportmember 20 has a small diameter of, for example, 1 mm, and, in order toprevent the support member 20 from deviating or fluctuating in apositional relationship with respect to the chip 3, etc, due to heat,the support member 20 is made of the same material such as, for example,Kovar as that of the stem as well as the fiber guide 6 to provideidentical coefficients of thermal expansion. In this connection, Kovaris well suited as a material for the support member 20 because ofminimal plastic deformation of the material when heat is appliedthereto. Advantageously, the support member includes a slenderdeformation portion 33 which has a hole 21 and which is deformable, anda flat base portion 34 which is fixed to the stem 1; however, as canwell be appreciated, the support member may have another configurationas will be described more fully hereinbelow.

The cap 27 may also, for example, be made of Kovar, with the cap 27being adapted to be placed on the ring-shaped sealing wall 15 and beingadapted to be hermetically fixed by, for example, seam welding.

FIG. 6 provides an example of another support member generallydesignated by the reference numeral 20, wherein a root portion of thedeformation portion 33 adjoining the base portion 34 is fashioned as aconstricted portion 35 so as to be readily bent or curved. Theconstriction portion 35 is easily curved or bent because it gives riseto a stress concentration when an external force is applied to the headpart of the support member 20'. Since the deformation portion 33 isprovided with the hole 21 for enabling an insertion of the optical fiber7, the part formed with the hole 21 also causes a stress concentrationeven when the optical fiber 7 and the fixing material 22 are receivedtherein. In some cases, the support member 20' might break down in anarea of the hole 21; however, when the constriction portion 35 isprovided, the stress concentration in the constriction portion 35 isgreater and the support member 20' curves or bends in the constriction35 which is effective to prevent an occurence of a breakdown of thesupport member 20'.

In the embodiment of FIG. 7, a deformation portion 33' and a baseportion 34' of a support member generally designated by the referencenumeral 20" each have a rectangular cross-sectional configuration;however, the embodiment of FIG. 7 achieves similar effects to theeffects achieved in the embodiment of FIGS. 2-4, that is, the supportmember 20" may well have a cross-sectional configuration other than around rod configuration. Since the embodiment of FIG. 7 has arectangular base portion 34', it is possible to readily effect a correctorientation of the support member 20" when fastening the same to thestem 1.

In the embodiment of FIG. 8, a fiber guide 6' penetrates or extendsthrough a hole 21 provided in the support member 20 and is fixed thereinby, for example, a silver paste 36. A diameter of the fiber guide 6'was, for example, 500 μm, with a diameter of the hole 21 being, forexample, 800 μm. The support member 20, the fiber guide 6', and the stem1 are made of the same material such as, for example, Kovar so as toprevent fluctuations or deviations in the positional relationship withrespect to the chip 3, etc. due to heat. By virtue of the fact that thesupport member 20, fiber guide 6', and stem 1 are made of the samematerial, each of these elements would have identical coefficients ofthermal expansion. Since, in the embodiments described hereinabove, theoptical fiber 7, which is made of silica, is directly fixed in the hole21 of the support member 20, the silver paste 36 would be unsuitable asa fixing material since, with the silver paste 36, large thermalstresses act on the optical fiber 7. In contrast, according to theembodiment of FIG. 8, the fiber guide 6 is extended so as to fix theoptical fiber 7 in the hole 21 of the support member 20 through thefiber guide 6', so that the silver paste 36 can be used as the fixingmaterial. The silver paste 36 has a favorable bonding property with thefiber guide 6' and has a higher reliability than a resin. Due to theconstruction of FIG. 8, the coefficients of thermal expansion of thecontact parts between the stem 1 and the fiber support member 20, andbetween the fiber guide 6' and the fiber support member 20 becomesubstantially equal, and the thermal stress tending to act on theoptical fiber 7 can be reduced to a very small level. Furthermore, amechanical stress which is exerted from the support member 20 in finallyadjusting optical axes after a fixation of the optical fibers 7 isabsorbed to some extent by the extended fiber guide 6', so that anyexcess mechanical stress does not act on the optical fiber 7.Consequently, it is possible to prevent the degradation of thephotocoupling efficiency and also enhance the reliability of the device.The support member for supporting the optical fiber 7 may well be madeunitary with the stem 1 by machining a stem material at the formation ofthe stem 1 without being formed as a separate component. Since, in thiscase, the positional accuracy of the support member relative to the stem1 would be based upon the machine operation, it is possible to attain ahigher accuracy. Additionally, the optical fiber 7 is fixed in the holeformed in the support member and the hole need not always be circularbut, as shown in FIG. 9, a support member generally designated by thereference numeral 20a may be provided having, for example, a square hole37.

It is also possible, as shown in FIG. 10, to provide a support membergenerally designated by the reference numeral 20b having a hole 38provided with a fine slot 39 through which the silver paste 36 ispoured. It is also possible to provide a construction wherein, ratherthan a hole, the optical fiber 7 may be supported by a groove orprotrusion (not shown) provided in the support member. Furthermore, withregard to the fixing material for fixing the optical fiber 7, even witha special solder which is used for bonding a glass, the optical fiber 7can be positioned and fixed centrally of the circular hole by theadhesive force of the solder.

As shown in FIG. 11, a support member generally designated by thereference numeral 20c may be provided with a constriction portion 41. Inthis construction, it has been determined through experimental studythat with a constriction portion 41, the support member 20c is suitablefor practical use in that, when a force is applied to the head part ofthe support member 20c, a movement of the deformation portion 33 can becarried out easily so as to facilitate the adjustment of the opticalfiber 7, and that, when heat is applied, the plastic deformation of thesupport member 20c itself is relatively small. More particularly, theexperiments were conducted with various components having the followingdimensional relationships. A diameter of the support member 30 was 1 mm,a height of the deformation portion 33 from the upper surface of apedestal portion 34 was 2.6 mm, a diameter of the hole 21 was 0.4 mm, adiameter of the pedestal portion 34 was 1.8 mm, a length of the top ofthe support member to a center of the hole was 1.5 mm, a width of theconstriction portion 41 was 0.4 mm, a smallest diameter of theconstriction portion 41 was 0.6 mm, a length from a center of the hole21 to a middle of the constriction portion 41 was 0.6 mm, and a heightfrom the upper surface of the pedestal portion to a center of theconstriction portion 41 was 0.45 mm.

After an optical fiber 7 has been fixed, the position of thephotocoupled end part 8 for receiving the light can be corrected.Therefore, even when the positional deviation of the optical fiber 7 hasoccurred during the fixation of the optical fiber 7, etc, the opticalaxes of the chip 3 and the optical fiber 7 can be aligned at the finalassembly stage before packaging, so that a laser diode device of highphotocoupling efficiency can be provided.

By virtue of the above-noted effects, the photocoupled state can beadjusted at the final stage of assembly, so that the occurrence of themisalignment of the optical axes can be reduced, and the enhancement ofavailable percentage is achieved.

Moreover, with the invention, the adjustment of the optical axesalignment of the optical fiber 7 with respect to the chip 3 can besimply made by merely bending a support member supporting the opticalfiber 7 in the desired direction so that the production efficiency isincreased.

furthermore, the photocoupled end part 8 of the optical fiber 7 isaccommodated in a circular hole 21, and is supported in a state in whichthe whole periphery of the optical fiber 7 is uniformly pulled or drawnby a liquid fixing material 22. Therefore, the optical fiber 7 isautomatically centrally positioned in the hole 21, the positionalaccuracy of the photocoupled end 8 becomes high, and the ratio ofacceptance as to the optical axis alignment of the optical fiber 7 tothe chip 3 increases. Accordingly, the optical axis alignment correctingoperation in which the support member is bent need not always beperformed for all products, and the number of man hours for the assemblyof the device can be reduced.

Additionally, when the support member 20 for supporting the opticalfiber 7 is provided with a constriction portion 35 at a lower partthereof, a stress concentration easily arises, and the bendingcorrection of the support member is facilitated.

Also, with the support member being formed of the same material as thatof the stem 1 and fiber guide 6 for supporting the optical fiber 7, itis possible to equalize the coefficients of thermal expansion.Therefore, even when a temperature change arises, the positionalrelationship between the chip 3 and the optical fiber 7 does not change,and a stable optical communication can be maintained.

Furthermore, with a construction such as proposed by the presentinvention wherein the fiber guide 6' is extended to the fiber fixinghole 21 of the support member 20 and the optical fiber 7 is fixed with asilver paste 36 through the fiber guide 6', the coefficients of thermalexpansion of the contact parts or areas between the stem 1 and the fibersupport member 20 and between the fiber guide 6' and the fiber supportmember 23 become substantially equal so as to enable a reduction in athermal stress acting on the optical fiber 7. Moreover, since the fiberguide 6' absorbs a mechanical stress to some extent, any excessmechanical stress does not act on the optical fiber 7. Therefore, theeffect of preventing the degradation of the photocoupling efficiency isfurther enhanced.

While in the above, the invention has been chiefly described as beingapplied to an optical communication technology employing a laser diode,as can readily be appreciated, the invention is not restricted theretobut rather the invention is applicable to, for example, an opticalcommunication technology employing a light emitting diode or a lightemitting device in which a light emitting element such as a laser diodeor light emitting diode is assembled. Thus, the present invention isapplicable to any device which meets at least the condition that a lightemitting element and an optical fiber are assembled.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to one having ordinary skill in the art, and we therefore do notwish to be limited to the details shown and described herein, but intendto cover all such modifications as are encompassed by the scope of theappended claims.

We claim:
 1. A method of assembling a light emitting device with anoptical fiber comprising the steps:(a) preparing a stem having apedestal portion; (b) fixing supporting means for an optical fiber onsaid stem, said supporting means having a hole and being deformable inthree orthogonal directions; (c) mounting a laser diode chip on saidpedestal portion of said stem; (d) inserting a portion of the opticalfiber into said hole, and immovably fixed in said hole; and after saidinserting; (e) adjusting said supporting means in at least one of thethree orthogonal directions to determine an optimum position of aphotocoupled end part of said optical fiber relative to a light emittingportion of said laser diode chip and fixing the supporting means in theoptimum position.
 2. The method as claimed in claim 1, wherein:saidsupporting means includes a round rod-shaped support member.
 3. Themethod as claimed in claim 1 wherein:said laser diode chip is asemiconductor laser diode chip.
 4. The method as claimed in claim 1wherein:said end part of said optical fiber is polished with a taper. 5.The method as claimed in claim 1 wherein:the fixing of the optical fiberis carried out by a resin which fills said hole.
 6. The method asclaimed in claim 1 wherein:fixing the optical fiber is carried out by asilver paste which fills said hole.
 7. The method of claim 1wherein:said supporting means and said stem are made from the samematerial.
 8. A method of assembling a light emitting device with anoptical fiber comprising the steps:(a) fixing supporting means for anoptical fiber on an attachment means, said supporting means having ahole and being deformable in three orthogonal directions; (b) mounting alight emitting means on a portion of said attachment means; (c)inserting a portion of the optical fiber into said hole and fixing saidoptical fiber immovably in said hole, and after the inserting; (d)adjusting said supporting means in at least one of the three orthogonaldirections to determine an optimum position of a photocoupled end partof said optical fiber relative to a light emitting portion of said lightemitting means and fixing the supporting means in the optimum position.9. The method as claimed in claim 8 wherein:said supporting meansincludes a round rod-shaped support member.
 10. The method as claimed inclaim 8 wherein:said light emitting means is a semiconductor laser diodechip.
 11. The method as claimed in claim 8 wherein:said end part of saidoptical fiber is polished with a taper.
 12. The method as claimed inclaim 8, wherein:the step of fixing the optical fiber is carried out bya resin which fills said hole.
 13. The method as claimed in claim 8,wherein:the step of fixing the optical fiber is carried out by a silverpaste which fills said hole.
 14. The method of claim 8, wherein:saidsupporting means and said attachment means are made from the samematerial.